Centrifugal switch device



June 14, 1949.

G. LEVESQUE Du RosTu CENTRIFUGAL SWITCH DEVICE Filed July 20, 1945Patented June 14, 1949 CENTRIFUGAL SWITCH DEVICE Georges Levesque duRostu, Paris, France, as-

signor to Societe Anonyme Andre Citroen, Paris,

France Application July 20, 1945, Serial No. 606,226

In France June 27, 1942 Section 1, Public Law 690; August 8, 1946 Patentexpires June 27, 1962 3 Claims.

My invention has for its object spark advancin control device forinternal combustion engines and is intended to reduce the number ofparts and to simplify the operations of assemblage.

Said centrifugal switch device is based upon the centrifugal action of amass carried by one or several springs secured without an intermediatefulcrum or like member at one end to the driving shaft and at the otherend to the camshaft. By the action of the centrifugal force the masstends to move away from the axis of rotation, thus causing the spring todeform elastically and the angular set of the driving shaft to vary withrespect to the camshaft.

Preferably, the spring consists of a steel wire or the like formed ateither end thereof with a loop received in a groove provided in eachshaft. The mass is fitted on the spring so that it cannot swingthereabout.

According to one peculiarity of the subject matter of the invention thebreaker arm together with the pivot and the adjustable contact arecarried as a whole by a sheet-metal member received in an annular recessprovided in the casing.

The simultaneous adjustment of th initial spring stress and of the leadmagnitude is obtained by means of a ring member secured on the drivingshaft and formed with abutments which are set with respect to each otherat 180 plus the amount of the adjustable lead and which correspond toabutments spaced through 180 provided on the camshaft.

A preferred embodiment of the subject matter of this invention will nowbe more particularly described, reference being had to the appendeddrawings wherein:

Fig. 1 is a vertical cross-sectional view.

Fig. 2 is a plan view corresponding to Fig. 1, the upper cap being takenaway.

Figs. 3, 4 and 5 show the timing device in front, side and plan viewrespectively.

Fig. 6 is a detail view of the timing device, while Fig. 7 is a planView of the upper side of the abutment ring-member of the same.

Fig. 8 is a. similar View of the member coopating with said ring member.

Fig. 9 shows a detail in cross-sectional view through a plane passingthrough the medial part of the mass.

Fig. 10 illustrates a detail of another form of securing the mass. I

Essentially, the ignition device comprises the 2 driving shaft I and thecamshaft 2 which drives the circuitbreaker; the whole is housed in acasing 5 on which the adjusting device 6 is mounted.

The ignition control mechanism (Figs. 3, 4 and 5) comprises a drivingshaft l alined with the camshaft 2. The angular set of these shafts withrespect to each other is obtained by means of one or several symmetricalsprings I. Each spring is secured at one end to shaft l and at the otherend to shaft 2.

Preferably, the spring consists of a steel Wire formed at either endthereof with a loop 8 received in a groove 9 in the shaft; a pin 26fitted in a recess 21 (Fig. 9) or a flat portion 28 (Fig. 10) retainsthe loop from slipping in the groove and moving about the shaft.

Said spring is curved at the place where the mass 4 is attached, samebeing made for instance of two halves provided with a groove havin thesame radius of curvature R as the spring and assembled by means ofrivets l0. As shaft I rotates the mass or masses 4 by the action of thecentrifugal force will tend to move away from the axis of rotation whichresults in an elastic deformation of the spring and a shifting of thedriving shaft with respect to the camshaft, and consequently a variationof the angular set.

Breaker arm I I, pivot l2 and adjustable contact 6 are carried as awhole by a sheet-metal member 13 secured by a screw M to the casing 5(Fig. 2). For that purpose, said casing is formed with an annular recessIS in which the sheetmetal member I3 is fitted; said recess also retainsthe cardboard insulator l5 of the leading-out ter minal l1. It is to benoted that the breaker arm II is operated by cam II' formed on part 3(see Figures 1 and 2).

The sheet-metal member I3 is bent at its end 18 to carry the pivot 12 ofthe circuit-breaker. Tapped at its other end is a hole 20 for thetungsten-contact set screw.

For defining the starting point and the extent of the lead it is onlynecessary to adjust the tension of spring I.

In the case of an ignition control device with no secondary timing it ispossible to modify together the starting point and the extent of thelead. To this end the circuit breaker rigid with camshaft 2 is formedwith two abutments 2| corsponding to the abutments 22 on ring-member 23secured on the driving shaft I. The abutments A on shaft 2 are set atfrom each other, while the angular spacing of the abutments on shaft Iis 180 plus the desired lead magnitude. A sim.

3 pie operation in either direction of washer 25 is sufficient foradjusting the lead.

Ring-member 23 is provided with an adjusting slot 24. In Qrder to retainsaid, ring from. being carried with as thelooking nut is beingtightened, provision is made between said ring-member 23 and the nut ofa washer 25 formed with a flat poi tion fitting a corresponding flatportion machined on the threaded end of shaft I.

What I claim as my invention and desire tov secure by Letters Patent is:

1. An automatic spark advancing mechanism for internal combustionengines including at least one mass submitted to centrifugal force,formed by two superposed symmetrical members-showing a groove in thecooperating surfaces thereof, a.

spring to which said mass is directly secured; a. driving shaft, a camshaft the angular shifting of which with reference to the driving shaftdefines the variation in the lead and means for securing the ends. ofthe. spring respectively csaid wo shafts, the radius of curvature of thespringin the" part. to which the mass; is secured match-. ing the radiusof curvature of the groove.

2. automatic spark advancing mechanism for internal, combustion engines.including at least one mass; submitted to, centrifugal force, a. yield-.ingi-wire ending with a loop. ateach. end. a-drivin shaft, a cam shaftthe angular shifting of which with reference to the, driving shaftdefines the variation in the lead, each of said two. shaftsbeingprovided near their cooperating ends with an annular groove inwhich the corresponding the variation in the lead, each of said twoshaftsbeingprovided near their cooperating ends wit an annular groove inwhich the corresponding looped end of the wire is inserted, said springending: with fiat ends, each shaft including a flat part for engagingthe corresponding flat end of the spring and preventing any rotation ofthe spring round the shaft considered.

GEOBGE EVE QUE- 1 R KEEEBENCE GITED The following references are; ofrecord in. the

I file of this patent:

UNLTED. STATES PATENTS.

Number Name Date,

1,691,757: Dick Nov. 13, 1928 FORE GN PATENT Number Country Date 84,870.Austria. -,g July 25,, 1,921

